Aeroplane propeller



1- 29, 1931- GLANSCHNIG 1,825,184

AEROPLANE PROPELLER Filed Aug. 16, 1929 2 Sheets-Sheet 2 Inventor mama Sept. 29,1931 V reggae;

UNITED STATES rafraurorr cs IGN'ATZ emnscnme, or any, mnmnn, as'sreivonor ONE-HALF no m KAZLAWSKI, or ARY, mnrnm 'mnornmn rBorm-Lna Application mea Aug-M1118,- 1928. Serial Io. asaaea.

This invention relates to aeroplane protaken substantially on "line 55 of Figure, pellers and an object of the invention is 4 and looking rearwardly. provide a propeller that creates the maxl- Figure 6 1s anenlarged' planlview of the mum of pulling power with a -relat1vely. hub cap;

5 small amount of resistance, by reason of the Figure 7 is a fragmentaryvertical secfact that at the hub the blades of the protion' in detail. taken through the hub capand peller are constructed upon the principle of hub illustrating the latch in locked-posia screw to permit the air to pass through tion. 1 I o 7 ith ut b t ti n v Figures 8, 9 and are sections taken sub- 0 Another object of the invention isto prostantlally on line 88, 9-9, and 1010 of vide a propellerthat aids, in the cooling of Figure 1, illustrating the rolling pitch. of the the motor, that rovides a rolling blade blades. which not only ma es the propeller stronger, Figures 8a, 9a, and 10a are diagrammatic but reduces the resistance againstthe reviews taken substantially on lines 8-8, 9,9,

. 15 volvin .of the propeller. and l0l0 of Figure 1, illustrating the an- In the drawings, wherein like. refer- Furt er objects of the invention are to gular pitch of the blade from the end to the provide in a manner as hereinafter. set hub thereof, and, forth, a propeller of the character referred Figure 11' is a fragmentary plan View of to, that is strong, compact and durable, very a modified form of the invention.

20 reliable in its intended purpose, very si-m- Referring to the drawings in detail, 15 I0 ple in its method of assembly, adaptable indicates a solid conical shaped hub cap for installation to any type drive shaft, and formed of aluminum. On the base of the is comparatively inexpensive to manufachub cap there is formed an annular groove ture and assemble. 16 adjacent the periphery thereof to pro- With the foregoing and other objects in vide for countersinking the forward ends of view, the invention consists of a novel conthe hub bolts to be presently described. The struction, combination and arrangement of I outer walls of the hub cap extend slightly parts, as will be more particularly described below the face of the base for the purpose and illustrated in the accompanying drawof forming an annular flange 17. A bolt ings, wherein .is disclosed an embodiment of 18 has the head end cast integral in the hub so the invention, but it is to be understood'that cap with the threaded end projecting from changes, variations and modifications may the base along the axis of the cone. The be resorted to without departing from the flange 17 has a slot 19 extending therespirit of the claims hereto appended. through and a spring latch 20 is held in superimposed position over the slot by a once characters denote'corresponding parts rivet or holdfast device 21 secured at one throughout the several views: end of the latch and to the wall of the hub Figure 1 is a front elevation of theprocap. The other free endof the latch is free peller with the hub cap removed and showtoibe flexed.

ing the propeller revolving clockwise inthe An arcuate shaped lug 22 is secured to 99 direction of the arrows. the inner face of the latch by a rivet 23 and Figure 2- is a top plan View of the prois of such thickness that it normally propeller in the assembledrelation on the crank jects radially from the inner face of the shaft. I flange 17 by the action of the spring latch 45 Fi ure 3 is a side view of the propeller so that it will be detachably locked in a re- I showing the outer or free end of one of the cess on the hub to be presently described.

blades. The hub cap 15 is adapted to have the apex Figure 4 is an enlarged sectional detail leading and projecting forwardly from the view at the hub portion of the propeller. propeller blades, with the base thereof to be 59 Figure 5 is a verticalsection in detail the trailing portion, and when the hub cap 15 is connected to the hub of the propeller a continuous conical shaped hub is formed.

The propeller blades and the hub are preferably cast integral and formed of an aluminum copper alloy, but it is also w thin the contemplation of this invention to form the same of wood. In forming the alloy, it has been found that one pound of copper added to the aluminum of each propeller is sufiicient. Care must be taken to add the copper in the form of a fine wire so as to make a homogeneous casting. If lump copper were used in the alloy there would be segregated areas of copper in the casting and owing to the difference in weight of the copper there would be an unbalanced propeller.

The segregation would be due to the different melting point of aluminum and copr. The better way to form the alloy would be to mix the aluminum and copper together in the molten states.

The hub of the propeller is indicated at 24 and is of frusto-conical shape with the frustum leading. The leading peri hery adjacent the forward face is forms with an annular shoulder 25 over which is seated the flange 17 on the hub cap. Extending axially from the leading face ofthe hub is a peripherally threaded circular socket 26 that is adapted to receive the threaded projecting end of the bolt 18. The bolt is threaded in such a manner that it turns in the threads of the socket 26 opposite to the rotation of the propeller, to. eliminate the possibility of the hub cap being detached from the revolving hub.

Spaced radially from the cavity 26 is an annular series of openings '27 through which extend a plurality of bolts 28. The forward ends of the bolts are threaded" and have nuts 29 thereon which are seated in the annular groove 16, when the hub cap 15 is attached to the hub 24. The series of bolts 28 have the heads 30 thereof coupled in abutting .relation to the flange 31 of the crank shaft 32 which may lead from any prime mover such as an internal combustion engine. When the hub cap 15 is screwed into the socket 26 and the flange 17 is seated tight against the shoulder 25, a cavity 22 formed on the periphery of the shoulder 25 provides an alined seat for the lug 22. When the lug 22 snaps into the seat 22' the cap is locked to the hub and requires the latch 20 to be flexed before the cap can be removed.

A pair of propeller blades, indicated generally as 33 and 34, project diametrically from opposite sides of the hub, the edges .at the free ends of the blades being rounded as in Figure 1, but it is within the contemplation of my invention to modify the ends of the blades to a curve having a radius equivalent to the-length of the blade, as in Figure 11.

vBeginning at its outer end, each blade has a pitch of sixty-five degrees with respect to the plane of rotation of the ropeller, and the blade rolls or twists with decreasing pitch toward the hub. Adjacent the hub the blades have a pitch of thirty de rees with respect to the plane of rotation o the propeller.

This rolling or twist of the blades is illustrated in the diagrammatic views, 8a, 9a, and 1001. As the hub is approached the twisted blades pass through less space and therefore the decreased pitch causes the air currents to pass through the vortexaround the hub of the propeller, thereby eliminating backpush found in many propellers.

It will be under-stood that the blades are relatively inclined in opposite directions from the plane of rotation of the propeller. In the model tested, it was found that the roll-of the propeller blade as above described gives it greater tensile strength. By using a testing apparatus, it was found that the propeller formed in accordance with the present invention made twelve rev olutions per minute around a circle having a diameter of twenty-five feet while a representative model of propellers now in use made only five revolutions per minute around the same circle with the same driving power.

Beginning at the outer end the blades thicken uniformly to the point where each blade merges with the hub 24. The thick ening of each blade is clearly illustrated in Figures 8, 9 and 10 of the drawings which illustrate sections taken on lines 8-8,99, and 10-10 of Figure 1. In a conventional sized propeller in accordance withthe present invention, the blade is four inches wide at the free end to approximately one-third the distance to the hub and from the'latter point, the blade should taper regularly from four inches to three and one-half inches ylvige where the inner end merges with the Moreover, in a conventional sized propeller in accordance with the present invention, there is a space of two times three or more inches between the blades at the hub to permit the passage of air through the blades at the hub.

Referring particularly to Figure 9 where a cross section of a blade is shown, looking toward the hub, the trailing face is indicated as 35, and at the rear of the forward edge of the blade, the face is curved as at 36, the remainin portion of the trailing face being fiat. The curved portion 36 extends from the tip of the blade to the hub of the propeller. The leading face 37 of each blade is also flat throughout the length of the blade, except for a rounded or curved flat faces is thus given a maximum pullin part 38 at the rear edge of this leading face, which curved part also extends from the tip of the blade to the hub of the propeller.

Thus the leading ed e 39 of the leading face, and the trailing e ge 40 of the trailing face of each blade is flat, while the rear trailing edge, of the leading face and the front trailing edge of leading face are rounded.

The two faces 35 and 37 are in parallelism throughout the length of the blade, regardless of the thickness of the blade, and of the twist or acuteness of the angle or pitch of the blade.

The blade with parallel and'substantially power, while the uniform width of these faces also adds to the pulling power, which power is present from the tip of the blade to the hub of the propeller, i. e. throughout the length of the blade. The curves 36 and 38 at the leading and trailing edges of the blades enable the blades to pull more easily and to cut more easily through the air. Having described my invention, what I claim is:

1. An aeroplane propeller comprising a hub, a pair of blades formed integral with the vhub and disposed on the diametrically opposite sides thereof, said blades inclinin in opposite directions from each other, each of said blades rolling from an angle of sixtyfive degrees with respect to the plane of the rotation of the propeller on its outer end to an angle of thirty degrees at a point where each blade merges with the hub, and means on the hub for connection to a drive shaft of a prime mover, the margin at the upper edge of each blade flat on the leading face and curved on the trailing face and the margin at the lower edge of each blade curved on the leading face and flat on the trailing face to provide iprulling' power the entire width of the blade om end to hub.

2. An aeroplane propeller comprising a hub, blades formed integral with the hub and disposed on the diametrically opposite sides thereof, said blades inclininginopposite directions from each other, each of said blades rolling from an angle of sixty-five;

degrees with respect to the plane of rotation of thirty degrees at a point where each blade merges with'the hub, and means on the hub -mover, the marglln for connection to a drive shaft of arprime at the ummr edge of each blade flat on t e leading face and curved on the trailing face and the margin at theloweredge of each blade curved on the leading face and fiat-on the trailing face to provide pulling power the entire width of the 7 blade from end to hub.

3. An aeroplane propeller comprising a hub, blades formed integral with the hub on the diametrically opposite sides thereof and face and curved on the trailing face and the margin at the lower edge of each blade curved on the leading face and flat on the f trailing face to provide pulling power the entire width of the blade from end to hub..

' 4. An aeroplane propeller comprising a g hub, to form a continuous cone when assembled on the hub, blades formed integral with the hub on the diametrically opposite sides thereof and inclining in opposite directions from each other, each of said blades rolling from an acute angle with respect to the plane of rotation of the propeller on the end of the blade to an acute angle of lesser degree where the blades'merge with the hub and means on the hub for connection to a crank shaft'of a prime mover, the margin at the upper edge of each blade fiat on the leading face and curved on the trailing face and the margin at the lower edge of each blade curved on the leading face and fiat on the trailing face to provide pulling power the entire width of the blade from end to hub.

5, A propeller having a plurality of blades each twisted to provide an angle of attack substantially throughout the length of the blade, said bladesveach having parallel, flat, leading and trailing faces, the forward edge of the trailing face being rounded and'the rearward edge of the leading face being rounded substantially throughout the length of the blade.

In testimony whereof I afiix my signature. IGNATZ GLANSCHNIG.

of the propeller on its outer end to an angle 

